:!?:GNU GRUB (short for GNU GRand Unified Bootloader) is a boot loader package from the GNU Project. GRUB is the reference implementation of the Free Software Foundation's Multiboot Specification, which provides a user the choice to boot one of multiple operating systems installed on a computer or select a specific kernel configuration available on a particular operating system's partitions.

VERSION 1

The master boot record (MBR) usually contains GRUB stage 1, but can contain another boot loader which can chain boot GRUB stage 1 from another boot sector such as a partition's volume boot record. Given the small size of a boot sector (512 Bytes), stage 1 can do little more than load the next stage of GRUB by loading a few disk sectors from a fixed location near the start of the disk (within its first 1024 cylinders).

Stage 1 can load stage 2 directly, but it is normally set up to load the stage 1.5., located in the first 30 KiB of hard disk immediately following the MBR and before the first partition. In case this space is not available (unusual partition table, special disk drivers, GPT or LVM disk) the install of stage 1.5 will fail. The stage 1.5 image contains file system drivers, enable it to directly load stage 2 from any known location in the file system, for example from /boot/grub. Stage 2 will then load the default configuration file and any other modules needed.

VERSION 2*& Stage 1: boot.img is stored in the master boot record (MBR) or optionally in any of the volume boot records (VBRs), and addresses the next stage by an LBA48 address (thus, the 1024-cylinder limitation of GRUB legacy is avoided); at installation time it is configured to load the first sector of core.img.& Stage 1.5: core.img is by default written to the sectors between the MBR and the first partition, when these sectors are free and available. For legacy reasons, the first partition of a hard drive does not begin at sector 1 (counting begins with 0) but at sector 63, leaving 62 sectors of empty space not part of any partition or file system, and therefore not prone to any problems related with it. Once executed, core.img will load its configuration file and any other modules needed, particularly file system drivers; at installation time, it is generated from diskboot.img and configured to load the stage 2 by its file path.& Stage 2: files belonging to the stage 2 are all being held in the /boot/grub, which is a subdirectory of the /boot directory specified by the Filesystem Hierarchy Standard (FHS).

2. LILO :question:

WHAT IS LILO :question:

:pencil2: LILO does not depend on a specific file system, and can boot an operating system (e.g. Linux kernel images) from floppy disks and hard disks

:pencil2: LILO (LInux LOader) is a boot loader (a small program that manages a dual boot) for use with the Linux operating system.

:pencil2: LILO (Linux Loader) is a boot loader for Linux and was the default boot loader for most Linux distributions in the years after the popularity of loadlin.

:pencil2:Most new computers are shipped with boot loaders for some version of Microsoft Windows or the Mac OS.

loadlin is a Linux boot loader that runs under DOS or Microsoft Windows (95, 98 or Me only). It allows the Linux system to load and replace the running DOS/Windows without altering existing DOS/Windows system files

loadlin and the Linux kernel are both files on a file system accessible to DOS/Windows. It loads the Linux kernel into memory from a file. It also places various configuration parameters into memory, and transfers control to the kernel. The kernel reads these parameters, initializes and runs, replacing DOS/Windows completely.

The SYSLINUX Project is a suite of lightweight master boot record (MBR) boot loaders for starting up IBM PC compatible computers with the Linux kernel. Primarily developed by H. Peter Anvin, the SYSLINUX bundle consists of several separate systems used for different purposes, including ISOLINUX, PXELINUX and EXTLINUX